README.md in string-cases-0.0.3 vs README.md in string-cases-0.0.4

@@ -40,9 +40,25 @@
 ```ruby
 StringCases.singularize("users") #=> "user"
 StringCases.singularize("categories") #=> "category"
 ```
 
+### Constantize
+
+```ruby
+StringCases.constantize("SomeNamespace::SomeClass") => SomeNamespace::SomeClass
+```
+
+### Symbolize keys
+
+```ruby
+StringCases.symbolize_keys({"test1" => "test1val", "test2" => {"test2key" => "test2val"}}, recursive: true) #=> {:test1 => "test1val, :test2 => {:test2key => "test2val"}}
+```
+
+```ruby
+StringCases.stringify_keys({test1: "test1val", test2: {test2key: "test2val"}}, recursive: true) #=> {"test1" => "test1val, "test2" => {"test2key" => "test2val"}}
+```
+
 ## Contributing to string-cases
 
 * Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
 * Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
 * Fork the project.